(12Y) Kubin, H., Fink, H., Fetfe, Seifen, Anstrichmittel 63, 280 ( 1961). (13Y) Leeman, H. G., Stich, K., Helv. Chim. Acta 45, 1275 (1962). (14Y) Lench, E. R. H., Lewis, G. T., Chemist-Analyst 50, 18 (1961). (15Y) Pelletier, O., Campbell, J. A , , Anal. Biochem. 3, 60 (1962). (16Y) Polk, A., Flanagan, T. L., Van Loon, E. J., Ciin. Chem. 6, 558 (1960). (1iY) Rindi, G., De Giuseppe, L., BioChem. J. 78, 602 (1961). (18Y) Roe, J. H., Ann. A’. Y . -4cad. Sei. 92,277 (1961). (19Y) Roe, J. H., J . Bid. Chem. 236, 1611 (1961). (20Y) Toepfer, E. W., Polansky, M. hIacA., Hewston, E. M., Anal. Biochem. 2, 463 (1961).
(21Y) Tsen, C. C., i l x . 4 ~ . CHEM.33, 849 (1961). (22Y) Wawrzyczek, W.,2. Anal. Chem. 184, 191 (1961). (23Y) Yamaoka, T., Bitamin 21, 304 (1960). (24Y) Yoshida, K., Hosokawa, A , , Yoshida, s.,AfZk ‘)fed.J . 11, 13 (1961).
(1Z) BoKer, 5‘. E., Paabo, M., Bates, R. G., Clin.Chem. 7, 292 (1961). ( 2 2 ) Crespi, H. L., Katz, J. J., ilnal. Biochem. 2, 274 (1961). ( 3 2 ) Critchfield, F. E., Bishop, E. T., ANAL.CHEM.33, 1034 (1961).
(42) Forbes, J. IT7.,Zbid., 34, 1125 (1962).
(52) Gaebler, 0. H., Choitz, H. C., Clin. Chem. 6, 549 (1960). (6Z) Grisler, R., Kava, C., Recenti Progr. Mecl. 30, 438 (1961). ( 7 2 ) Hendry, E. B., Clin. Chem. 8, 246 (1962). ( 8 2 ) Zbid., 7, 156 (1961). (92) Mendelsohn, D., Levin, N. W., S. African J . Med. Sei. 25, 13 (1960). (1OZ) Mungall, T. G., Mitchen, J. H., ASAL. CHEM. 33, 1330 (1961). ( l l z ) Remington, J. w.9 Baker, c. H.9 Circulation Res. 9, 60 (1961). (122) Rodkey, F. L., J . Bid. Chem. 236, 1589 (1961). (132) Vaughan, B. E., Boling, E. A , . J . Lab. Clin. Med. 57, 159 (1961).
Coatings M . H. Swann, M. I . Adams,
and G. G. Esposifo
Coating and Chemical laboratory, Aberdeen Proving Ground,
biennial review contains the authors’ choice of the important contributicns to the analysis of coating materials from Sovember 1960 to Sovember 1962 since the previous summary (110). It is hoped that, in a n attempt to be selective, valuable publications have not been omitted. Other 5imilar reviews mere made within this period (88, 90), in addition to some on special subjects. I n the annual reviews of analytical methods for the examination of oils and fatty acids (51, 108), numerous references are made to instrumental techniques. Scwer techniques for analyzing lipides were presented in the collected lectures of the 1961 short course sponsored by the Xmerican Oil Chemists’ Society (68). A comprehensive, alphabetical list of analytical and other test methods that appear in U. S. and Canadian specifications on coating materials (84) was published in 1960. Some of the papers presented in a symposium (1) on the analysis of high polymers were collectively reprinted and include such subjects as resinography, chemical structure, pyrolysis techniques, tagged standards, polymer fractionation b y column methods, molecular orientation in polymer films, and chemical analysis. The application of infrared spectroscopy and gas chromatography to coating analysis mas reviewed by Brenner ( 1 2 ) ; a similar review including pigment analysis was made by Lamprecht (64). Wooldridge (120) reviewed the application of paper chromatography, ion exchange resins, and complexones t o the analysis of such paint components as dicarboxylic HIS
Md.
acids, polyhydric alcohols, and pigments and included some original procedures. A summary (60) was made of the qualitative and quantitative methods for the determination of the fatty and rosin acids present in tall oil. The 12th edition of the Gardner Laboratory manual on paint, varnish, and lacquer testing (54)was released in recent months. Parts I1 and I11 of “Analytical Chemistry of Polymers” (61, 62) dealing with techniques for the determination of chemical and physical structure have been published. GENERAL ANALYTICAL SCHEMES
Gas chromatographic examination of the products of thermal degradation and description of devices for obtaining or introducing pyrolyzates continue t o be the principal topic of discussion in coating analysis. Porter, Hoffman, and Johnson (96) describe a unit for pyrolyzing weighed samples a t ambient to over 500’ C. temperatures and state that their unit is adaptable to most commercial instruments. Barlow, Lehrle, and Robb ( 5 ) employed two degradation techniques, characterizing polymers by chromatograms of their degradation products a t a number of temperatures and observed quantitative yields. Hewi t t and Khitham (4’7) described their glass pyrolysis unit, which is suitable for both liquid and solid samples, and reviewed the literature on gas chromatographic identification of materials b y this method. I n still another paper on direct analysis of polymers (30) by thermal degradation, the pyrolyzates of nitrocellulose, poly(n-butyl methacry-
late), and poly(viny1 alcohol) were obtained and measured a t 650’ C. Jones and Moyles (57) explain the use of a simple unit for obtaining chromatograms of the pyrolyzates of acrylic and styrene polymers. The use of controlled pyrolytic conditions followed by fractional distillation and sometimes sublimation is reported b y Cleverley and Herrmann (19) for identifying elastomers and their additives from the infrared spectra of the isolated products. The application of the paper chromatographic technique to the identification of the pyrolysis products of elastomers mas reported (SI). In this procedure, mercuric acetate adducts of the $00” pyrolyzates were formed and the chromatographic patterns compared to those from known materials. Diphenylcarbaxone spray was used for detection and the study applied mostly to natural and synthetic rubbers. Paper chromatcgraphy was also used by Koda and Hirayama (83) for the detection of fatty acids and glycerides. Vargas (115) tabulated a variety of tests for the identification of polymers of styrene, isobutylene, chloroprene, vinyl acetate, and natural rubber. Estensive treatment of the subject of qualitative and “spot” tests for polymers and resins was presented by Lucchesi and Tessari (70). Color reactions for the detection of poly(viny1 alcohol), poly(vinyl acetate), poly(viny1 chloride), epoxy resins, urea-, thiourea-, and melamine- formaldehyde, methylated nitrogen resins, and dicyandiainide on fabrics have been described (25). VOL. 35, NO. 5, APRIL 1963
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A discussion and illustration of x-ray methods and their value to the paint industry (68) included diffraction, absorptiometry with mono- and polychromatic beams, and emission spectrography. A 160-page treatment of the subject of infrared spectroscopy as applied in the coatings field was issued ( 8 6 ) for use as a laboratory manual and includes 195 spectra and 2.59 literature references. This excellent work provides elementary but thorough coverage of basic theory, sample preparation, and analytical techniques for use with binders, pigments, and solvents. Perfetti and Miller (94)discussed the practical applications of optical analytical techniques in general to the study of organic coatings, emphasizing the value of infrared. T o widen the application of infrared spectrophotometry, Bishop (8) described equipment and techniques for studying polymers a t controlled temperatures on pressed KC1 disks. Haslam, Jeffs, and Willis (44) described their niethod for separating milligram fractions of various materials from the gas chromatographic instrument for examination by infrared spectroscopy duririg polymer analysis. Two papers on the application of nuclear magnet,ic resonance to coating materials have appeared. Johnson and Shoolery (56) measured the total number of hydrogen atoms in the molecule and the number of olefinic protons and from these measurements calculated iodine number and molecular weight, making comparisons to the chemical analysis. They included examination of tung, linseed, soybean, coconut, and safflower oils and obtained good agreement with iodine values obtained by Wijs solution, except in the case of tung oil which is known to give low results by the chemical method. Chen (16) supplied a rapid method for the analysis of butadiene-isoprene copolymer using high resolution nuclear magnetic resonance. Glover and Stanley (38) describe their ebulliometric apparatus for studying number-average molecular weights of polymers. A variety of solvents and their use in differentiating a series of resins by paper chromatography were examined by Weigel (119). The identification and estimation of pigments in a wide variety of pigment composit,ions were studied by Duiican (22) using reflectance spectrophotometry. A technique for estimating watersoluble copolymers in aqueous solutions by infrared spectroscopy was described (%), in which acetone was used as a n internal standard. Shapras and Claver (102) have determined small amounts of unreacted monomer in water emulsion latices by the use of gas chromatography. They used a hydrogen flame detector anti a 6-foot column of stearamido-
Attenuated total reflectance infrared has been applied to the analysis of alkyd and monomer-modified alkyd resins by Harris and Svoboda (40)with excellent analytical results. They determined phthalic anhydride, isophthalic acid, vinyltoluene, and styrene on a routine basis without prior chemical treatment of the resins. Ritchie (99) has classified the competitive, concurrent reactions by which estrrs and polyesters tend to break down thermally, with an explanation of most of the processes. An infrared spectrometric technique (36) was used to differentiate the copolymers of vinyl cyanide with acrylic acid, methvl methacrylate, and methyl acrylate. -4rapid qualitative tept for bisphenol-type epoxy resins in painted surfaces and a gravimetric method for quantitative measure of the eaoxy portion of most coating solutions based on these resins were reported (109). Infrared spectroscopy was employed (17) to analyze copolymers and mixtures of poly(methy1 acrvlate) and poly(viny1 acetate). The recommended conditions mere tabulated (103) for determining vinyl acetate in vinyl chloride-vinyl acetate copolymers by saponification and volumetric measure of excess alkali. Lehmann and Brauer (66) studied the volatile pyrolysis products of polystyrene and poly(met'iy1 methacrylate) a t various teniperatures with gas chromatography. They pvrolyzed the polymer in a glass boat surrounded by a 34-gage platinum heating coil connected to a variable transformer. RIiller, Samsel, and Cobler (76) determined acrylate and maleate esters in polvmers by combined Zeisel and gas chromatographic methods. Pasciak described his methods for the polarographic determination of styrene in polystyrene (92) and for methyl methacrylate in poly(methy1 methacrylate) (93). A technique for quantitatively separating esters of methacrylic acid from lacquer formulations, through saponification of the other components and subsequent treatment with acid, was published
propyldimethyl-8-hydroxyethyl ammo-
(111).
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0
ANALYTICAL CHEMISTRY
nium nitrate. Selsen, Eggertsen, and Holst (82) claim that as !ittle ab 0.05y0 of the residual monomers and other volatile organic compounds in aqueous emulsions can be measured by their procedure, which uses a vaporizer and a gas chromatograph. I n a publication on the analysis of printing inks 12), a number of tests applicable to resins, mostly qualitative, are described in detail. Advantages of a new technique for obtaining unsupported paint films for various studies are mentioned ( l a g ) , in which the coating is applied to a strippable film on a solid substrate. SPECIFIC CLASSES OF HIGH POLYMERS
Finley (sa) measured poly(viny1 alcohol) in paper coatings spectrophotometrically without interference from starch by using the green complex formed by reaction with iodine and boric acid in solution. A method (6) for analyzing cellulose acetobutyrate involves saponification to obtain combined acetic and butyric acid content, then determination of butyric acid alone by ouidation r i t h dichromate in sulfuric acid. A similar procedure (33) for analj.zing cellulose acetobutyrate bases t h r calculation on saponification value, titration of acid, and weight of cellulose separated. The use of paper chromatography for the rapid identification of cellulose esters and ethers (72) was reported as suitable for all except niethj 1and hydrouyethylcellulose. Vollmann (11'7) discussed the disadvantages of using diphenylamine for identifying nitrocellulose and described his recommended procedure, using Griess reagent. The glycerol content of varnishes made by cooking tung oil m-ith alkyl-phenol resins was used (46) as a basis for measuring the amount of tung oil in the system. The authors stated that isolation of fatty acids for this purpose m-as not useful, because of their reaction with the phenolic resin portion. Stephens and Lawrence (106) determined the abietic-type dienoic acids in rosin products spectrophotometrically after stabilizing the color produced by the Liebermann reaction. Haslam and Jeffs ( 4 3 ) illustrated, with chromatograms, the separation and identification of terpenes and related substances in synthetic and commercial sample.; by gas chromatography. The analysis of silicones by optical methods was investigated (113); a rapid mass spectrometer procedure for determining methyl and phenyl chlorosilanes in mixtures was described by Hirt (@).
SPECIFIC CONSTITUENTS
Haslam, Hamilton, and Squirrel1 (42) applied the oxygen flask combustion method to the detection of such elements as nitrogen, chlorine, fluorine, phosphorus, and sulfur in polymers and plasticizers. Palit (91) explained his technique for detecting such groups as sulfate, amine, halogen, hydroxyl, and carbouvl in polymers by dye partition and interaction and measured the carboxyl groups quantitatively. Programmed temperature gas chromatography has been applied to the identification of 19 of the most frequently encountered carboxylic acids in alkyd and polyester coating resins (27). In this procedure, the resins are treated directly with lithium methoxide to form methyl esters b y transesterification followed by separation on polar and nonpolar c d -
umns. Two similar mall tical methods for separating carboxylic acids by thinIs;;er chromatography appeared sipiult3neously ( 1 1 , Y6). Both used silica gel b,ut8different developing solutions and jnrluded such acids as tartaric, citric, phthalic, terephthalic, benzoic, p-toluic, phosphoric, maleic, and fumaric. The fatty acid series did not separate under the sanie conditions. The pcilarographic &termination of terel)lithalic acid was reportctl ( 7 ) . Gas chromatographie separation of the esters of six benzene +ids: three isomc~rictricarl)oxylic acids, and the three isomeric phthalic acids, usiiig $-cyanoetliyl ethers of polyhydric akohols on grountl unglazed t.ile, has bcen tlescribed ( 2 7 ) . llurnieks and C;ont'er (SO) einplo!~d ultraviolet spec$ro\),hc&ametryto ticJterinine benzoic acid in refiiied pht1i:ilic~ xnhydride, while IIoorc 2nd 1Ieinqtein (79) used gas c1iroiiistii~rrzl)liy for the samc purpose. Ifartforti (4l ) ilrvclolied a rapid spec$i.u!hotometric i)rocedure for determiniug itaconic. aconitic, citric: and fumaric arid's using t,he Fnrtli and Herrniann reaction. The usc of progrminied teinpcrature gas chromatogra!~liyt,o identify the polyhydric, alcohols iii eyntlietic resins appqqred in two parts (2.5>8 6 ) , separating hhe polyols as awtntes aft,er liberation from the resirie 11y treatment wit'h amines. Paper chromatography was also ustd ( 9 8 ) to identify the glycol pomponents of unsaturated polyest,er resins aftcr rapid rcmoi-a1 of the dicarhoxylic acids a i d residual alkali from pponificst'ion. Mono- and dipentagrythritol in samples of technical pentapythritnl w r e me:asured wilh a n 11y Carazaola ( 1 4 ) using rrccurac\- of s-ray diffraction. Stotzler and Smullin il0Sj h a w contributed a method for determining liydrosyl number of polyethers, that should be very useful in its ai)plication to ineny other resins and ~ m h a p ssol\.ent,s. Tliey acetylated the samples with wet,ic anhydride in ethyl acetate, i i k g p-toluenesulfonic acid as catalyst. witliin 1.5 minutes a t 50" C. The hydroxyl content was calculated after titration with alcoholic alkali. 3 I u r p h ~ .( 8 1 ) calculated hydroxyl nuniOer of alkyd resins by infrared absorption nnd discusrd thc influenre of water and temperature vari:+tions on the analysis. Iheher (21j dcsvribed in detail his procedure for determining hydroxyl value of unsaturntcd polyester resins. X gram of saml)lc in 10 mi. of 1 to 1 c,lilorobenzene-acetolic. was treated with an excess of 0.5.1- phenyl isocyanate for 5 minutes at 20" C. and the excess reagent titrated ivitli 0 . 5 9 diisobutylamine, in chlorobenzene, with bromophenol blue indicator. Since carboxyl groups also reacted, a correction was applied through a separate titration with alkali. Hydroxymethyl groups in pheiiolic resins m r e estimated (24) by treat-
ing x i t h phenoi in hydrochloric acid, then measuring the unchanged phenol. The acid number of poly(ethy1ene terephthalate) was calculated from potentiometric titration of 2-gram samples in a 7 t o 3 mixture of o-cresol and chloroform (73). Levitsky and Sorwitz (67) determined the nitrogen in nitrocellulose from the absorbance of the nitrate band in the infrared region, using fixed cells and tetrahydrofuran as solvent. .1rapid method for t'he microdetermination of sulfur in monomeric and polymeric organic compounds containing also nitrogen, halogen, and alkali metals was reported (65), with 0.37, accuracy. The combustion was conducted in an oxygen flask and samples containing from 2 t.0 40yo sulfur were analyzed. Schroder and Kaurick (100) employed sodium fusion and a n ion-exchange column to measure fluorinc volumetrically in high polymers. Schulz reviewed (101) conventional methods of determining free formaldehyde in papers, melanine resins, and solutions: t,hen recommended separation in the vapor phase a t 150" C., and determination by tJhesulfite method. Colorimetry was used to nieasurc hydroquinone, benzoquinone, and the monomethyl et,her of hydroquinone in acrylic monomers (%), The color produced by t'he reaction of diphenylolpropane with diazo-p-nitroaniline was used to estiiiiat'e and cont,rol free diphenylolpropane in epoxy resins ( 9 ) . The aniperometric titration of the total phenolic group content of epoxide resins in diniethylformamide has also been described (51). Turler and Hog1 (112) described their procedure for extracting and identifying organotin compounds in poly(viny1 chloride), using thin-layer chromatography. H o f h a n n (60) published a procedure for det,ermining phenyl mercury compounds and total mercury in paint products. The difference in the dielectric constant of a dioxane extract of pigment pastes and printing ink colors, before and after passage through a drying agent', was used by Ohme (87) to measure the mater content. OILS A N D FATTY ACIDS
Choudhury (18) tested the applicability of acidified commercial bleaching solutions as reagents for eqtiniating unsaturation of fats and oils. 9 method for estimating saturated fatty acids in mixtures (74) involves broinination in ether followed b y formation of urea adducts, filtration, regeneration, and weiqhing of the isolated qaturated acids. Horrocks (53) and awociates calculsted relative katharometer responses foi nieth11 wters of fatty acids of two homologous series and listed relative response data for saturated esters and for Cla unsaturated methyl esters. for
use in quantitative separation by gas chromatography. In a later work, Horrocks and Cornwell (52) obtained simultaneous estimation of fatty acid composition and the ester glycerol ratio by gas-liquid chromatography. They converted glycerol esters quantitatively to their corresponding acetate esters by hydrogenolysis with lithium aluminum hydride followed by direct acetylation. hlin-a et al. (77) presented a gas chromatographic technique for the characterization of fatty acids, whereby each component on the chromatogram is expressed by equivalent chain length t o a homolog of the saturated straight-chain monocarboxylic acid. Metcalfe and Schmitz (75) supplied details for esterifying fatty acids, forming methyl esters in 2 minutes, using boron trifluoride as catalyst. Vorbeck et al. (118) made a quantitative comparison of four methylation techniques and reported variations for mixtures of low molecular weight fatty acids, in which cas? they recommended the use of diazomethane. Otherwise, with high molecular weight acids they obtained comparable results. Kaufmaiin and Buscher (b9) conducted their entire analysis of the fatty acids in alkyd resins on paper, including the saponification. A critical examination of the use of gas chromatography for identifying the oil content of organic coatings was made b y Zielinski and associates (12f); i t is based on characteristic fatty acid distribution in different oils. They included in their study the effects of such special treatments as heat. maleic adduction, blowing, bodying, and liming, reaction with cyclopentadiene, vinyltoluene, etc. Stine and Doughty (107) presented the results of their work in tall oil and turpentine analysis, including description of the chromatographic techniques, preparation of methyl esters, and interpretation of data. Methods for t h e quantitative analysis of tall oil fatty acids by gas chromatography were compared by Iden and Kahler (64). They used methyl margarate as an internal standard to circumvent errors in the totalarea method that result when nonvolatile methyl esters are present. They evaluated three esterification methods with comparable results, and determined correction factors for each of the methyl esters studied. The factors Tvere interchangeable between different instruments containing thermoconductivity detectors. ASSOCIATED MATERIALS
The use of ultraviolet absorption spectrophotometry for analyzing solvent mixtures was illustrated with spect,ra (4). The application of infrared spectrometry t o lacquer solvent analysis was also discussed in detail (65). VOL. 35, NO. 5, APRIL 1963
37 R
Haslam, Jeffs, and Killis (45) included details for isolating solvents from adhesives, lacquers, and other coatings in their description of their preferred method of separating components b y gas chromatography followed by identification by infrared. The application of programmed temperature gas-liquid chromatography to the direct qualitative and quantitative analysis of lacquer solvents was illustrated (28) along with details of the method of correction and normalization of peak areas from the chromatograms. About 15 solvents were included. An error in this investigation was later corrected b j the authors (29). Xylene isomers and ethylbenzene were separated by gas chromatography (114) with a 9-foot column packed with Celite mixed with SY0 Bentone 34 at 43’ C. and a strontium-90 detector. Case (16) used 1,8-diaminonaphthalene or m-phenylenediamine as liquid phase to separate m- and p-xylene. Ashton (3)made an extensive investigation of the methods for the quantitative chemical determination of t h e hydrocarbon content of lacquer thinners. The examination of chlorinated solvents by combinedgas chromatography and infrared spectrometry was illustrated (86). Detection and measure of the major constituents of turpentine by gas chromatography have been described (13). Cook and associates (20) separated high boiling plasticizers by gas chromatography using a short column and operating at 235” C. They were interested in determining dibutyl and dibenzyl phthalate in commercial benzylbutyl phthalate. A polyphenyl ether and Carbowax mixture was used as substrate by Ghanayem and Swann (36) for the gas liquid chromatographic analysis of glycol mixtures. Lucchesi and Hirn (6‘9) modified an earlier technique for complexometric titration of total iron in driers. Graske (39) used masking and demasking techniques t o determine cobalt, zinc, manganese, and lead in mixed driers by complexing the cations in four different titrations. Borchert (10) reviewed the procedures for determining metals in pigments and driers volumetrically with complexing agents. Verna, AIathur, and Dnyal (116) published a cerimetric method for determining red lead and lead peroxide and indicated several advantages over the iodometric technique. Details were supplied (78) for determining 0.4 to 7% lead in paint used for toys, b y the x-ray fluorometric method. Hoffmann (49)described his method of detecting lead in dried paint films and for estimating the extent t o which it is responsible for sulfide staining. A procedure for the gravimetric determination of lead followed by the titration of zinc with Trilon B was presented b y Malevannyi (71) as being applicable to zinc whites.
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ANALYTICAL CHEMISTRY
LITERATURE CITED
(1) ANAL.CHEM. 33, 1810-36 (1961). (2) Apps, E. A., Paint Manuj. 32, 193 (1962). (3) Ashton, H. E., Ofic. Dig. Federation SOC.Paint Technol. 33, 775 (1961). (4) Australtan Paint J . 5, 23 (1961). (5) Barlow, A., Lehrle, R. S., Robb, J. C., Polymer 2 , 27 (1961). (6) Bartels, U., Hoyme, H., Faserjorsch. Teztiltech. 11, 503 (1960). ( 7 ) Bezuglyi, V. D., Novik, E. Y., Zavod. Lab. 27, 544 (1961). (8) Bishop, W. A, ANAL. CmV. 33, 456 (1961). (9) Bogatyrev, P. hl., Kavyazhskaya, E. A., Sporykhina, V. S., Lakokrasochnye Materialy i ikh Primenenie 1960, 53. (10) Borchert, O., Plaste Kautschuk 6,562 (1959). (11) Braun, D., Geenen, H., J . Chromatog. 7 , 56 (1962). (12) Brenner, Nathaniel, Ofic. Dig. Federation SOC. Paint Technol. 33, 51 (1961). (13) Brus, G., Legendre, P., Niolle, G., Ann. FaL. 54, 142 (1961). (14) Carazzola, G., Chim. e ind. (Milan) 42, 858 (1960). (15) Case, L. J., J . Chromatog. 6 , 381 f19611. (16) Chen, H. Y., ANAL. CHEM. 34, 1134 (1962). (17) Chinai, S. N., Campbell, R. H., Ibid., 33, 577 (1961). (18) Choudhurv. R. B. R.. J . A m . Oil ’ Chemists’ So; ’37, 198 (1960). (19) Cleverley, B., Herrmann, R., J. Appl. Chem. 10, 192 (1960). (20) Cook, C. D., Elgood, E. J., Shaw, B. C., Solomon, D. H., rlv.4~. CHEM. 34, 1177 (1962). (21) Dreher, B., Farbe Lack 67, 703 (1961). (22) Duncan, D. R., J . Oil & Colour Chemists’ Assoc. 45, 300 (1962). (231 , -, Ernst. W.. Sorkin. XI.. Teztil Rundschau 15; 433’(1960).‘ ‘ (24) Ershov, B. P., Mosina, -4.S., Zhur. Anal. Khim. 15,243 (1960). (25) Esposito, G.’ G., ANAL.CHEY. 34, 1173 (1962). (26) Esposito, G. G., Swann, hl. H., Ibid., 33. 1854 11961). (27) i b i d . , 34, 1048 (1962). (28) Esposito, G. G., Swann, 11. H., Otfic. Dia. Federation SOC.Paint Technol. 33. 1125 f 1961). (29) >bid., p. 1460. ( 3 0 ) Ettre. L., Varadi. P. F.. AXAL.CHEY. J k , 752 (1962). ’ (31) Feuerberg, H., Kretschmer, W., Weigel, H., Kautschuk Gummi 14, 218 (1961). (32) Finlev. J. H.. - 4 s ~ ~CHEX. . 33, 1925 (1961). (33) Franz, J., Plaste Kaufschuk 7 , 493 (1960). (34) Gardner, H. A , Sward, G. G., L‘Physical and Chemical Examination of Paints, Varnishes, Lacquers, Colore,” 12th ed., Gardner Laboratory, Bethesda, Md., 1962. (35) Gentilhomme, C., Piguet, A., Rosset, J., Eyraud, C., Bull. SOC.Cham. France 1960, 901-6. (36) Ghanayem, I., Swann, IT.,ASAL. CHEM.34, 1847 (1962). (37) Ginzburg, T‘. I., Flegontova, L. M., Zavod. Lab. 27, 392 (1961) (38) Glover, C. A., Stanley, R. R., ANAL. CHEM.33, 447 (1961). (39) Graske, A., Ofic. Dig. Federatzon SOC.Paznt Technol. 33. 855 (1961). (40) Harris, R. L., Svoboda, G. R., ANAL.CHEU.34, 1655 (1962). (41) Hartford, C. G., Ibid., 34,426 (1962). (42) Haslam, J., Hamilton, J . B., ~
~
\ -
Squirrel1,D. C. M.,Analyst86,239( 1961). (43) Haslam, J., Jeffs, R., Ibid., 87, 658 (1962). (44) Haslam, J., Jeffs, A. R., Willis, H. A., Ibid., 86, 43 (1961). (45) Haslam, J., Jeffs, A . R., Willis, H. A., J . Oil & Colour Chemists’ Assoc. 45, 325 (1962). (46) Hauck, K. H., Alarquardt, W., Farbe Lack 67, 699 (1961). (47) Hewitt, G. C., Whithani, B T., Analyst 86, 643 (1961). (48) Hirt, C. A., ANAL. CHEX 33, 1786 (1961). (49) Hoffmann, E., Australian Paint J . 4 , 23 (1960). (50) Hoffmann, E., 2. anal. Chem. 1961, 182. 193. (51) Horner, J. W., J . Am. Oil Chemists’ SOC.39, 369 (1962’. (52 Horrocks, L. A,, Cornwell, D. G., J . Lipid Res. 3 , 165 (1962). (53) Horrocks. L. A.. Cornwell. D. G., Brown, J. B:, Ibid., 2, 92 (1961). 154) Iden. R. B.. Kahler. E. J.. J . A m . Oz
